<!doctype html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<canvas id="myCanvas" width="200" height="100">
<!--此处放置用于绘制图形的JavaScript代码。-->
</canvas>
<script type="text/javascript">
var canvas = document.getElementById("myCanvas"); 
if (canvas.getContext){ 
    alert("您的浏览器支持canvas!");
}else{ 
    alert("您的浏览器不支持canvas!"); 
}
</script>
</body>
</html>  
